Document stacking arrangement



June 30, 1970 D|G|L|o ET AL 3,517,924

DOCUMENT STACKING ARRANGEMENT Filed May 2, 1968 INVENTORS FR A. DIGILIO BY JO L. RAE

ATTORNEY United States Patent 01 fice 3,517,924 Patented June 30, 1970 3,517,924 DOCUMENT STACKING ARRANGEMENT Frank A. Digilio, Medfield, and John L. Rae, Roxbury, Mass., assignors to Honeywell Inc., Minneapolis, Minn., a corporation of Delaware Filed May 2, 1968, Ser. No. 726,076 Int. Cl. B65h 29/16 US. Cl. 271-75 14 Claims ABSTRACT OF THE DISCLOSURE An improved stacking arrangement for reliably translating computer record documents from a prescirbed inject station into a prescribed pack in a stacking hopper, successively; this arrangement exhibiting the features of: a centered pulley paired belt transport; associated roller and guide means adapted to direct documents smoothly along a stacking path; a common trans-, port drive whereby a single roller is rotatably driven to, in turn, drive an associated belt and to also synchronously drive a second belt and roller system, with a document trapped therebetween; also a bumper roll arrangement driven by this belt system and adapted to thrust records into the stacking hopper and keep them aligned there, spaced away somewhat from the point of entry into the hopper.

BACKGROUND, FEATURES TAUGHT As attempts are made to increase the rate and efficiency at which unit records (e.g. punched card documents) are diverted and stacked, workers in the art recognize that certain problems are encountered. Conventional stacking arrangements suffer from such defects as being overly complicated or expensive; tending to congest the stacking path and restricting access to elements therein (e.g. for servicing or releasing a jammed card, etc.); as not transporting cards fast enough or with enough reliability and freedom from risk of jam; or as not providing a smooth enough diversion path in diverting cards from an IN station to an OUT station; or not maintaining them sufiiciently flat and undistorted while being so transported and diverted. The present invention provides improvements along these lines and offers features in a centered belt stacking transport arrangement which serve to alleviate these, and related, difiiculties.

Workers in the art wil lalso reflect that a desirable stacking arrangement should also be adapted to better protect the physical condition of documents; for instance, avoid impacting document edges against rigid abrading elements, etc. and thereby damaging them. It should alsobe adapted to stack documents reliably despite prescribed variations in document dimensions (lengths, thicknesses). For instance, cards should be stacked reliably and quickly despite common variations in their physical characteristics and dimensions resulting from environmental changes (e.g. from humidity; such as card-warp, slight dimensional variations due to manufacturing tolerances, etc.). Conventional stacking devices do not readily satisfy these needs, especially for the high-speed stacking needed in data processing and most especially when a fairly wide range of document dimensions must be handled (such as 80-column and punched cards). This invention is directed toward meeting these needs.

An associated problem with such prior art stacking arrangements is design complexity, in that such devices typically involve too many intricate, expensive, parts; or too many moving parts, subject to service needs, wear, failure, etc.; or too many trapping, or blocking elements, impeding access to the stacking mechanism or to documents trapped therein. The present invention involves providing an improved stacking arrangement adapted to solve the foregoing needs, while at the same time radically simplifying stacker design.

Thus, according to salient features of the invention, improved stacking means are provided which exhibit the features of a centered stacking assembly arranged to be disposed centered along a stacking path and engage documents registered therewith at an inject point to transport them a stacking location, being adapted to resiliently capture opposite surface portions of an injected document and in conjunction with an opposed central assjefmbly, driven thereby, and to quickly translate the document along this path to a somewhat convenional stack container, the while maintaining outboard document surfaces (leading and trailing edges of a card) guided along this path, with guide roller means, also driven by the centered assembly.

Thus, it is a general object to provide the aforementioned features and advantages, as well as similar ones, and. to meet the aforementioned, and related difiiculties. A related object is to provide an improved stacking transport arrangement for injecting documents at high speeds and. in prescribed alignment into registration with a document stack in a prescribed hopper. A related object is to provide such an arrangement adapted to divert such documents and translate them smoothly from an input orientation to be aimed toward this stack in prescribed relation and kept aligned and undistorted during this translation. A related object is to provide such an arrangement according to a centered belt stacking assembly. Another related object is to provide such features including a pair of trapping belts and arranged to -grip the mid-section of such documents and transport them along a stacking path. A related object is to also provide release-stacking surface means adapted to urge the following document and into the stack unidirectionally and keep it there.

' Another related object is to provide such an assembly also including bumper means including smooth metal surfaces adapted to transport documents into alignment with the stack and maintain them aligned therewith. A further object is to provide a single common driving source for the aforementioned transporting and document-guiding surfaces. A further object is to arrange such a release-stacking means including a release pulley so disposed with respect to a drive pulley so that the belts driven thereby are frictionally inter-engaged, in free, unrestrained fashion, being biased against one another for this and also for more positively engaging an intermediate transported document.

Another object is to arrange such a release pulley to thrust trailing document edges toward the stack and keep them there. Still another object is to arrange said belts to be presented adjacent an IN-station on opposed pulleys, one of which is resiliently biased to open the inter-belt nip upon introduction of documents of prescribed thickness, while also being stop-limited to avoid damaging contact of the belts in the inter-pulley area.

The foregoing and other objects, features and advantages of the invention wil be apparent from the following, more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings, wherein like reference characters denote like elements.

FIG. 1, a rear elevation view of a stacking apparatus embodiment of the invention, from the side opposite the stacking hopper, with some elements removed or simplified for the sake of clarity; and

FIG. 2, a side sectional view along lines 22 of the embodiment in FIG. 2.

DESCRIPTION Referring to FIGS. 1 and 2, the stacking apparatus embodying the invention will be understood by those skilled in the art to comprise a novel centered belt stacking arrangement including a pair of cooperating transport belts BU, BL and associated apparatus adapted to engage punched cards, or like documents, at their center-section, to translate them from an inject-station (or IN-locus; e.g. see card C-1 on inject-guide TG) quickly, under precise control and reliably, to a prescribed eject-station, (or OUT-locus; e.g. see position of outgoing card -0 in FIG. 2), and to thereby successively stack cards in a stacking hopper (see pack CS on hopper bed SP) as understood in the art.

Workers in the art will recognize that the illustrated stacking transport embodiment is shown in operative combination with a rather typical stacking environment, schematically indicated, which will be understood as comprising the stacking zone and hopper portion of a punched card handling apparatus of known type. Here, the punched card documents are presented (such as from an upstream document processing and transport station) along an inject-guide platform TG (as indicated by upstream arrow Fu), to the presented in prescribed engageable relation with the stacking transport, such as by being pushed in an inject-direction (arrow Fin) by a conventional diverter means DP (when their mid-sections register along stackaxis C/L) and thus be presented at the in-nip II between belts Bu, BL. Moreover, in the course of being translated from this in-nip by the improved stacking arrangement, such documents will be understood as being ejected (such as indicated for card 0-!) in FIG. 2) into a conventional stacking hopper arrangement. In this hopper, a pack of ejected documents CS is kept aligned (on bed SP) and, conventionally, retained by a resilient pusher means 13 and related elements, well-known in the art (e.g. as commonly associated with stacking hoppers for card readers, card sorters, card punches and like document data processing apparatus). Also, associated with this stacking arrangement is a conventional resilient stop-spring 11 mounted from a portion of the machine frame, such as rigid mounting bar 15. The stacking platform SP (or hopper bed) is conventional in comprising a generally fiat, card-supporting surface on which cards are stackable upright on edge (generally vertically). Stack pusher 13 will be understood as conventionally mounted on bed SP for yielding movement toward and away from the eject locus (that is, relative to the approximate locus of card C-0 and pack-engaging portion of pulleys P, L etc.) Pusher 13 is fragmentarily indicated, but well understood in the art and, for instance, may be spring-biased toward this card-out poistion by a suitably arranged spring (not shown, but see force-arrow Pp), acting to keep the flat sides of the cards aligned as pack CS grows, pusher 13 being retracted the while back along bed SP.

It will also be understood that card-ejection into the stacking hopper is intended to be generally conventional. That is, as the card is thrust by the stacking transport into the eject locus (assumed by card C-0), and therebeyond, it will be understood that the card will continue to be thrust (such as by the hubs, or smooth roll surfaces, of bump-pulley P and associated outboard rolls PL, PR) up toward stop spring 11, to be impacted thereagainst stoppingly; thereafter the card will settle down with its trailing edge resting upon bed SP in alignment with the cards in pack CS. In the course of being so ejected, the card leading edge will contact, and slide along, the flat side of the last card stacked (or along pusher 13 etc. in the case where C-0 is the first card in the pack). Stop spring 11 may comprise any resilient energy-absorbing, damping means for gently engaging upward moving card edges and dissipating its kinetic energy quickly so that it rebounds to take its place in proper stacked alignment.

Referring now to particulars of the centered stacking assembly, and particularly to the upper and lower stacking belts (BU, BL respectively thereof), the following features will be noted. A prime feature is that the upper stacking system comprises a driving drum pulley D disposed centrally of the contemplated card-inject locus (even in the case of cards of different lengththat is, pulley D) is centered along document center-line (stackaxis) C/L. Pulley D is intended to constitute the primary, sole driving member in the translation arrangement, and is adapted to cooperate with an opposed driving means, such as lower opposed drive pulley LD and the intermediate belts carried thereon, or with equivalent means. Pulley D is thus intended to be rotatably mounted from a fixed location (on the machine frame) and to be rotatably driven, continuously, such as by a motor M. According to' an associated feature, pulley D is afiixed on a drive shaft D8 which, in turn, constitutes the shaft of the adjacent motor M (both phantomed, FIG. 1) which is fixedly mounted from a machine frame portion, such as a convenient sidewall SW. Although other means for mounting and driving pulley D may be employed, it will be apparent that this (cantilevered) mounting and driving arrangement, in the indicated manner, is especially advantageous. For instance, the casing of motor M (only the casing is shown and will typically be cylindrical, this motor being any conventional means to drive pulley D, such as a fractional horsepower AC motor) quite obviously can provide a cantilevered support for pulley D, as well as conventionally housing the motor parts, etc. Pulley D is provided with a suitable cylindrical, belt-engaging surface (or toothed-track-at least about its central periphery) so that upper belt BU may mesh therewith when entrained thereabout and be driven thereby as illustrated and well known in the art. So disposed, belt BU will be presented in document-engaging relation with lower drive pulley LD and the lower belt BL (similarly entrained and engaged on LD). Thus, belts BU, BL preferably comprise like timing belts (being resilient, of conventional toothed construction-e.g. of Dacron-filled polyurethane about 30 mils thick plus teeth), while pulleys D, LD are accordingly similarly toothed in registry with the belt widths. As noted below, a like (central) toothed track P-t is also provided about bump-pulley P. However, unlike D, P preferably has its track P-t inset below the rest of the (smooth, metal) pulley preiphery. Thus, with pulley P, outboard roll surfaces are preferably provided on both sides of the belt track, comprising smooth metal surfaces for guiding registering card-portions (e.g. for gently bumping stacked cards with P and for providing a rolling guide with D, together with stationary guide T G, etc.). This also helps prevent the belt from abrading the pack. The injection end T6 of guide plate T6 is also preferably projected beyond the entry (in) nip of the belts and is curved in conformance, generally, with the adjacent peripheral sector of pulley D, sufficient to pre-aim the transported document toward the pack (e.g. angle aa, toward eject-nip II-II, cf. below). Plate T6 is thus projected toward the prescribed eject-locus and is sufficiently wide to assure that (at least most of) the outboard portions of a document (outboard of axis C/L) are guided to be generally coplanar with its central, thrust portions engaged between belts BU, BL, and are kept relatively coplanar therewith. Such a guide can alleviate problems associated with distorting cards across their plane (e.g. card-bow, leading to drag, snagging corners, skew, etc.). As the FIG. 2 suggests, guide TG, T6 is relieved to accommodate the adjacent segments of the belts (and supporting pulleys D, LD) along the stacking path.

The lower drive assembly preferably comprises aforementioned lower drive pulley LD, together with an associated lower eject (release) pulley L and a lower idler pulley LI, with lower belt BL entrained, and tooth-engaged, about these three to be idled thereon (rather than driven thereby), somewhat conventionally. Thus, pulley LD is spring-pivotally mounted on a pivot mount LD-t of conventional construction and conventioally springbiased to resiliently urge the surface of pulley LD (and belt BL thereon) generally toward the surface of pulley D and (in registry with) belt BU thereon. Idler pulley LI includes a pair of conventional side flanges to keep belt BL laterally aligned (with belt BU, similarly confined by flanges on upper associated idler UI) as known in the art.

Thus, resiliently pivoted pulley LD will (together with pulley D and belts BU, BL) establish a yielding entry nip (in-nip, or inter-pulley/inter-belt gap) between the belts at their point of nearest tangency (minimum gap between pulleys D, LD). Preferably, toothed timing belts BU, BL touch (so that BU can drive BL idlingly when a document is not interposed) somewhat downstream of this entry-nip, and not in the gap-zone between pulleys D and LD. Of course, this entry-nip will be somewhat less than the minimum expected document thickness, but sufiicient to prevent belt scrubbing, or other belt contact or abrasion, in the absence of an interposed document, (e.g. for cards witha 7-mil thickness spec, a minimum inter-belt gap of about 3 mils was found suitable, e.g. also preventing damaging bounce-contact of BL against BU). Accordingly, an up-stop means, such as adjustable stop LDfiS, is provided to conventionally establish this minimum gap. Of course, the in-nip I-I will be somewhat larger than this inter-gap.

Idler pulley LI is mounted like LD, being mounted on a pivoting tensioning arm LI-t and similarly spring biased; however, simply to provide a conventional, prescribed resilient tensioning of belt BL. Eject pulley L is fixedly mounted from, and rotatably journaled in, the machine frame (as are the other pulleys, though this is not shown, being conventional) and is constructed to somewhat conventionally engage belt BL (tooth-engagement) in guiding, idling fashion (as a free-rolling guide driven by the belt-teeth). According to another feature, pulley L is preferably so disposed with respect to pulley D, to guide TG, TG and to stack bed SP, as to direct belts BL, BU along a prescribed transport (stacking) path (along the normal to locus IIIIII, at angle aa with bed SP). This orientation is intended to aim documents into prescribed relation with pack CS. Pulley L is also disposed in prescribed relation with bumper pulley P (as described below-cg. to aim an ejected card in prescribed relation with stack CS; to disengage the belts and release the document prescribed distance from stop 11 and, to be presented for up-stacking by pulley P, etc.). Pulley L is also preferably up-set slightly above bed SP and slightly upstream of the bump-contact plane (of pulley P and rolls PL, PR with pack CS), so that belt BL may stack CS unidirectionally and keep them aligned there. Thus, belt BL will be guided on pulley L so as to flip-in documents (central trailing edge portions thereof) onto pack CS.

Upper belt BU may also be entrained about an upper idler pulley UI, fixedly journaled in a convenient portion of the machine frame (by means not shown but conventional) where such is desirable (e.g. to clear machine elements above pulley D, etc.). Upper belt BU is also entrained about bumper pulley P in a carefully prescribed manner according to another feature of the invention whereby a prescribed mode of card ejection is effected, as well as a bumping of pack CS to define its forward limit, i.e. to maintain CS spaced somewhat downstream of the stack entry zone (eject-locus) where succeeding documents will first project into the hopper and be flipped-in by belt BL (on idling pulley L). As stated, the teeth of BU engage those of track P-t. More particularly, pulley P is thus adapted to urge the upper (driving) belt BU with a prescribed bias against the lower (following) belt BL (as guided by pulley L) to positively engage and transport documents until they pass the release point IIIIII. Thereafter, pulley P (outboard roll surfaces thereof, surrounding track P-t) will cooperate with (inset) belt BL to complete. the stacking translation upstack documents by gently urging them (with its smooth metal bump-surfaces). Accordingly, documents will be understood as obliquely contacted with the last card" (in pack CS) and slid guidingly therealong (by P and, for a time, by the flip-in action of belt BL) to thereafter be finally, and gently, engaged against spring 11 and gently kept in place (bumped), aligned in pack CS as the new last card. Accordingly, the disposition of pulleys P and L (as well as of pulleys D and LD) is arranged to define an intermediate stacking path (the normal to IIIIII) so as to assume a prescribed oblique inclination (range of angles aae.g. about 20-30) with respect to the plane of stacker bed SP and pack CS. In turn, guide plate TG is disposed, relative the stacking assembly, so as to divert cards into the in-nip, and therebeyond, somewhat gradually; i.e. from their original attitude into the precise inclination of this path; (of course, if platform TG happens to already lie at angle am with respect to plate SP, there will be no need at all for bending it at TG or for turning the cards).

According to a further feature of the invention, the "centered eject pulleys P and L are preferably disposed relative to one another, and relative to the pack CS, such as to effect an improved eject-thrust of the documents. Thus, pulleys P, L are arranged so that the lower pulley L is disposed somewhat upstream of pulley P, sufficient to release the translated card (trailing edge thereof) along a prescribed release axis -lIlIII and thus leave the released card in a prescribed eject locus (corresponding to the location of illustrated card C-0). Here, the leading card edge will be disposed along the surface of (the last card in) pack CS and spaced a prescribed distance from stop spring =11. Thus, upon such release of a card (at III-III) from between moving belts BL-BU, the belts will impress surficient retained kinetic energy on the released card that it will continue toward stop spring 11 in up-stac fashion. However, the card will now tend to decelerate somewhat (e.g. due to bending and to less positive belt thrust, as well as to the drag associated with turning and sliding along stack CS). Then, smooth roller-surfaces on pulley P and rolls PR, PL will brush against the card and complete upstack thereof (until it contacts with spring 11). To maintain the turning portion of the released card C-0 somewhat engaged with these roller surfaces for upstack post-release translation, pulley P must (for given card widths) be so disposed with respect to bed SP and belt BL (on pulley L) that the trailing card edge is so confined as to bend the card against P for much of this post-release transport. Additionally, and according to a related feature, pulley L is also disposed with respect to bed SP so that belt BL helps to so confine the trailing edge of this document (of anticipated card-length) for much of this post-release transport (as well as flipping it in). Additionally, and according to a related feature, pulley L is also disposed with its outer, belt-engaging surface somewhat off-set with respect to the straight stacking path (i.e. along the normal to III-III, or the tangent between the intermediate outer surfaces of pulleys P and D) whereby to assure that belts BL, BU properly wrap about pulleys P, D and positively hold an intermediate card. Thus, stack belts BU, BL wrap somewhat about the periphery of pulley L (rather than simply passing tangent thereto). This will be understood to bias them to impart a more positive driving engagement by the belts until the final moment of release (of card trailing edge). Such an ofiset disposition will also advantageously assist somewhat in bending the leading portions of an ejected card about the periphery of bump-pulley P.

According to another feature, eject pulley L is preferably mounted on a shaft L-S (fixedly journaled from the machine frame in a manner not indicated, but conventional) with a pair of smooth, metal-surfaced left and right outboard guide rolls (LL, LR, respectively). Rolls LL, LR are affixed symmetrically on LS, on either side of L to guide adjacent outboard portions of a card and keep a card relatively fiat and unbowed while transported by belts BU, BL (eliminate card stress, edge snag, drag, etc.; as aforementioned regarding guide TG, TG'). Thus, shaft L-S carries left and right guide rolls LL, LR to be rotated thereby in synchronism with pulley P, being spaced symmetrically about pulley P so as to guide the outer portions of translated cards while being kept rotating at the transport speed (or allowed to freely idle, though this is less preferable). Similarly, a pair of left and right guide rol-ls (PL, PR, respectively), are mounted on a shaft P-S to be rotated in synchronism with bump pulley P and to similarly guide card outboard portion, during final (up-stacking) translation. Moreover, rolls PL, PR also help keep the last card properly aligned in pack CS, i.e. aligned fiat against packs and unbowed (lest it snag a following card, etc.). Such rolling outboard guide surfaces will be seen by those skilled in the art as advantageously cooperating with the aforedescribed centered stacking arrangement.

A fiat guide plate 17 is also preferably providedto help confine cards during final stacking and thereafter, comprising a flat plate segment, parallel to the face of pack CS (but set back clear from the bump roll surfaces of P, LP, RP, to allow operation thereof). Plate 17 is also curved to extend along the card path (cf. bent segment 17-e) about as far as the release axis IIIII'I. Plate 17 will be generally understood as adapted to guide outboard card portions between pulleys L and P and as a card-aligning backup for the thrust of the belts therealong (e.g. in the manner of guide TG, TG', being about as wide as a maximum card length, etc).

Although the drawings do not show it, workers in the art will understand that all the aforementioned elements are, in some way, mounted from fixed machine-frame portions (not shown since they are conventional, lest drawings be overly complicated, etc.); such as shaft and journal means for pulleys LI, UI, shafts L-S and P5, pivot brackets LD-t, LI-t, guide TG, SP, etc. Of course, one advantage to such a centered stacking arrangement is that the few, single elements may readily be mounted to minimize belt-trapping. For example, if all elements are mounted from wall SW, or associated frame portions on the right," FIG. 1, it will be seen that belts may very readily be removed and applied from the left.

SUMMARY OF OPERATION To summarize the foregoing description, and to illustrate a typical operation of the elements described, it will be assumed that a card, such as -1, has been introduced along the surface of guide plate TG, being thrust therealong in a controlled manner approximately until its mid-point coincides with the center-line of the stacking assembly. At this juncture, diverter plate DP will impact the card to divert it into the in-nip between centered, paired timing belts BU, BL which will be understood as kept continuously moving by drive pulley D (rotatably driven by motor M, of course-and by this alone, preferably), following belt BL being synchronously driven by free, frictional engagement with drive belt BU (between pulleys D-L). Thus, it will be understood that, until entry of such a card between stacking belts BU, BL, the continuous rotation of drive pulley D will serve to move engaged belt BU at a prescribed linear speed, BU also being directed about pulley P to synchronously rotate P (and rolls PR, LR). One advantage to this arrangement will be seen in the driven frictional engagement of following belt BL with drive belt BU, since BL is normally biased against BU in slight frictional engagement for this, in free space (no fixed ground backup), according to the relative disposition of pulleys D, L and P. This paired-belt, centered transport system will thus continually move the belt (both with an intermediate engaged document, and without it) at a prescribed speed, while dispensing with need for a second separate drive system for the following belt, or with the associated synchronizing means, etc. Of course, with lower drive pulley LD resiliently mounted, the introduction of document C-1 (of prescribed thickness) in the reduced gap between belts BU, BL, will act to resiliently back off LD somewhat (against the resilient urgings of its associated tension spring) and thus responsively open the nip. In this way the belt system can accommodate a prescribed range of document thicknesses, as well as serve to assure driving frictional engagement of the belts. Belt BL is also prevented, by stop LD-S, etc. from contacting belt BU, and thus not impacting it (e.g. bounce contact when a card exits) or abrading it, etc.

Next, with the entry of injected card C-1 into nip II to be engaged for transport between belts BU, BL, it will be promptly and rapidly swept away along the smooth curved surface of guide segment TG' (e.g. at about 200 in./sec.) and turn to be aimed toward pack CS, the while being bent somewhat around the periphery of pulley D (following the conforming curved end TG'). Thereafter, with the card held between the belts (biased together by the offset of pulley L), it will be transported linearly toward hopper plate SP (at the prescribed angle aa therewith). The mid-section of the card is thus pulled, by belts BU, BL, along the stacking path, outboard portions being kept aligned by rolling over the smooth, moving contact-surfaces of rollers LR, LL. As stated, the offsetting of pulley L helps to assure a slight bias engagement of the two belts and to hold the document frictionally therebetween and thus assure a positive drive at the prescribed constant speed.

The card will then continue to be translated until its leading edge projects above hopper bed SP, then obliquely striking the face of the last card in pack CS and, being diverted thereby, proceed upward about the periphery of bump pulley P (roll surfaces thereof, plus associated moving rollers PR, PL) along the stack-face and toward stop spring 11 (see card 0-0). The trailing card edge will generally follow until released from between the belts (to then, be flipped-in by belt BL). That is, after release from between belts BU, BL (at release axis III-III) the document will continue to be skidded up along the face of the last card, under the urging of its retained kinetic energy and, to some extent, the urgings of bump rollers P, PR, PL. As mentioned, a card (e.g. C-0) will be bowed somewhat and urged into engagement with these roller surfaces, both by pack CS (and the associated resilient pusher 13) and by opposed pulley rolls PL, PR, as well as by the trapping of its trailing edge along the surface of moving belt BL (as it moves along the flip-in zone adjacent bed SP). Belt BL will, then snap the engaged card edge against the face of pack CS, and down a bit, helped by the unfolding action of the card.

Thus, the trailing edge of the card will clear the periphery of this flip-segment of belt BL and of guide rollers LL, LR (contact surfaces thereof) and the card will snap-up straigh to be relatively coplanar with the last card in pack CS; then, continuing its travel a bit, begin to contact (its leading edge with) stop-spring 11. Thereafter, card C-l will be returned by stop 11, to rebound, down onto bed SP and assume its place in alignment as the last card in pack CS. The up-stacking roller surfaces L, LL, LR may now act to bump the card, keeping opposed portions aligned with pack CS (as will belt BL and associated rolls LR, LL for base portions of a last card). From the time the card is released from between belts BU, BL, it will be understood that it is to undergo a predescribed deceleration (e.g. from about in./sec. to approximately reset condition) so as to impact the stop-spring 11 somewhat more gently. It will be noted to provide maximum stacking rates, stop-spring 11 should comprise any suitable spring of known construction that will assure that the cards are brought to a stop without damage and promptly snapped out of the path of a following (incoming) card.

With apparatus embodying the invention and most of the features illustrated (and with elements being other wise of conventional construction) punch cards ranging in length of 80 columns to 51 columns have been reliably and very satisfactorily stacked at the very high speeds associated with data processing. For instance, 80-column cards have been nicely stacked at data processing speeds on the order of about 450 to 600 cards per minute.

While the invention has particularly shown and described with reference to the foregoing preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details, various substitutions and modifications of some or all of the features alone or together may be made thereoin without departing from the spirit and scope of the invention as claimed below.

What is claimed is:

1. A centered belt stacking transport arrangement comprising: stacking belt means arranged along a prescribed stacking axis, including timing pulley means adapted to be continually rotated and provided with belt-engaging pulley surface areas; movable document guide means disposed outboard of said pulley means for low friction guiding of confronting outboard document portions along a prescribed stacking path; timing belt means adapted to be entrained about said pulley means along said surface areas thereof so as to be continually driven therebyand to thereby translate documents along said path between an inject locus and an eject locus, said eject locus corresponding to the point of entry of documents into a pack in a prescribed stacking hopper, said pack being maintained in prescribed alignment therein; inject means to thrust said documents toward said inject locus and said stacking belt means for engagement therewith along the document mid-section at a prescribed transport speed.

2. The combination as recited in claim 1 wherein said timing belt means includes a drive belt; wherein said guide means including guide pulley means disposed along said path in opposed relation with said belt means and wherein said centered stacking belt means are also paired and include a second, following belt entrained about said guide pulley means and directed thereby into documentengaging relation with said drive belt means; said following belt being biased against said drive belt sufi'icient to trap said documents therebetween and to frictionally engage it to be driven by said drive belt at all times and thus effect said translation.

3. The combination as recited in claim 2 wherein said guide pulley means is resiliently mounted to present the following belt in yielding entry nip relation with said drive belt and to be resiliently biased against an interposed document, said guide pulley means being also stoplimited so as not to contact said belts abradingly in the area of said nip; said belts being friction-engaged in free space, downstream of said nip, to effect a biased engagement thereof.

4. The combination as recited in claim 1 wherein said arrangement also includes guide means adapted to divert said documents from said inject locus to said pack in a smooth curving transition along a curved document path so as to be aimed for impact obliquely and smoothly against said pack, said guide means including a transport plate arranged at said inject locus so as to present sad documents at said entry-nip, and extending therebeyond in a curved segment thereof adapted to so aim said documents.

5. The combination as recited in claim 4 wherein said belt means comprise a drive belt drivenly engaged on a first drive pulley means and a following belt guidingly engaged on a second follow pulley means so as to confront said drive belt along a portion of said path; wherein said follow pulley means includes a nip pulley means disposed in opposed relation with an associated drive pulley element in said drive pulley means and adapted to engage said follow belt; wherein is also provided guide plate means adapted tqpres'ent a smooth guiding surface for supporting documents at said inject station; said drive pulley and nip pulley means being disposed relative to one another, and toysaid guide plate means, so as to present the pair of belts thereon to, in turn, present an interbelt nip disposed relative to injected cards such that they are engageable between the belts by said inject means in a positive, reliable manner; and wherein said hopper includes stop means for terminating said stacking path and adapted to decelerate documents into alignment in. the pack.

7 6. The combinationas recited in claim 4 wherein said belt means comprise a drive belt and a cooperatively arranged follow belt driven thereby; and wherein is also included release pulley means arranged along the portion of the stacking path defined by coacting juxtaposition of said belts between said loci, being also arranged so as to direct one of the belt out of coaction with the other and thereby establish a prescribed release point for releasing documents with their leading edge located at a prescribed distance beyond the release point and at a prescribed decelerate distance from said stop means to be engaged thereby; said release pulley means also including associated functionally-integral roller surfaces for guiding outboard portions of said documents while they are transported along said path.

7. The combination as recited in claim 6 wherein said hopper also includes a bed surface supporting said pack; and wherein said release pulley means is disposed so that said roller surface portions are upset somewhat above the level of said bed surface to thereby urge document trailing edges toward said pack and prevent them from returning back along said path.

8. The combination as recited in claim 6 wherein said release pulley means is disposed relative to other pulley means so as to effect a free-space biased engagement of said belts.

9. The combination as recited in claim 1 wherein said pulley means includes a drive pulley and other associated pulleys; wherein said drive pulley is operatively coupled to be rotated by a prescribed motor means including a rotatable shaft means and a motor housing; said motor housing being attached toa fixed frame to so support said rotatable shaft means, with said drive pulley mounted rotatably thereon and thereby present said drive pulley in prescribed alignment along said path.

10. A centered belt stacking transport arrangement comprising: stacking belt means along a prescribed stacking axis for translating documents therealong and along a prescribed stacking path between an inject locus and an eject locus, said eject locus corresponding to the point of entry of documents into a pack in a prescribed stacking hopper, said pack being maintained in prescribed alignment therein; said hopper including stop means terminating said path; bumper roll means adapted to present smooth roller surfaces adjacent the entry face of said pack so as to complete the translation of documents along said path into said stop means and to maintain said documents in prescribed alignment against said pack; and inject means to thrust said document toward said inject locus and said stacking belt means for engagement therewith along the document mid-section.

11. The combination as recited in claim 10 wherein said belt means comprise a drive belt and a cooperatively arranged follow belt driven thereby; wherein is also included release pulley means arranged along the portion of the stacking path defined by coacting juxtaposition of said belts between said loci, being also arranged so as direct one of the belts out of coaction with the other and thereby establish a prescribed release point for releasing documents with their leading edge located at a prescribed distance beyond the release point and at a prescribed 1 1 decelerate distance from said stop means to be engaged thereby; said release pulley means also including associated functionally integral roller surfaces for guiding outboard portions of said documents while they are transported along said path; and wherein said bumper roll means comprise a bump pulley centered along said path with a central belt track inset therein to minimize beltpack contact plus a pair of outboard bump rolls driven in common with said bump pulley and disposed symmetrically therea'bout so that the roll surfaces of all these jointly engage the pack.

12. The combination as recited in claim 11 wherein said hopper also includes a bed surface supporting said pack; and wherein said release pulley means is disposed so that said roller surface portions are upset somewhat above the level of said bed surface to thereby urge document trailing edges toward said pack and prevent them from returning back along said path.

13. The combination as recited in claim 12 wherein said release pulley means and said bumper means are each adapted to be rotatably driven by entrainment therea bout of a respective belt and each rotatably journaled in a fixed frame.

14. The combination as recited in claim 12 wherein is also included eject guide means extending along said stack path opposite said release pulley means for maintaining document portions outboard of said mid-section aligned wtih the transported portions; and wherein is further included stop spring means arranged in said hopper so as to present a resilient stop establishing the end of said stack path and adapted to resiliently thnust documents impacted thereagainst into alignment vn'th said pack.

References Cited UNITED STATES PATENTS 2,012,561 8/19135 Grupe 271-87 X 2,884,243 4/ 1959 Stobb 27187 X 3,148,879 9/1964 Kistner 27l87 EDWARD A. SROIQX, Primary Examiner 

